ABSTRACT
Mycobacterium tuberculosis (Mtb) as well as nontuberculous mycobacteria are intracellular pathogens whose treatment is extensive and increasingly impaired due to the rise of mycobacterial drug resistance. The loss of antibiotic efficacy has raised interest in the identification of host-directed therapeutics (HDT) to develop novel treatment strategies for mycobacterial infections. In this study, we identified amiodarone as a potential HDT candidate that inhibited both intracellular Mtb and Mycobacterium avium in primary human macrophages without directly impairing bacterial growth, thereby confirming that amiodarone acts in a host-mediated manner. Moreover, amiodarone induced the formation of (auto)phagosomes and enhanced autophagic targeting of mycobacteria in macrophages. The induction of autophagy by amiodarone is likely due to enhanced transcriptional regulation, as the nuclear intensity of the transcription factor EB, the master regulator of autophagy and lysosomal biogenesis, was strongly increased. Furthermore, blocking lysosomal degradation with bafilomycin impaired the host-beneficial effect of amiodarone. Finally, amiodarone induced autophagy and reduced bacterial burden in a zebrafish embryo model of tuberculosis, thereby confirming the HDT activity of amiodarone in vivo. In conclusion, we have identified amiodarone as an autophagy-inducing antimycobacterial HDT that improves host control of mycobacterial infections. IMPORTANCE: Due to the global rise in antibiotic resistance, there is a strong need for alternative treatment strategies against intracellular bacterial infections, including Mycobacterium tuberculosis (Mtb) and non-tuberculous mycobacteria. Stimulating host defense mechanisms by host-directed therapy (HDT) is a promising approach for treating mycobacterial infections. This study identified amiodarone, an antiarrhythmic agent, as a potential HDT candidate that inhibits the survival of Mtb and Mycobacterium avium in primary human macrophages. The antimycobacterial effect of amiodarone was confirmed in an in vivo tuberculosis model based on Mycobacterium marinum infection of zebrafish embryos. Furthermore, amiodarone induced autophagy and inhibition of the autophagic flux effectively impaired the host-protective effect of amiodarone, supporting that activation of the host (auto)phagolysosomal pathway is essential for the mechanism of action of amiodarone. In conclusion, we have identified amiodarone as an autophagy-inducing HDT that improves host control of a wide range of mycobacteria.
Subject(s)
Amiodarone , Autophagy , Macrophages , Mycobacterium tuberculosis , Tuberculosis , Zebrafish , Amiodarone/pharmacology , Autophagy/drug effects , Animals , Zebrafish/microbiology , Humans , Macrophages/microbiology , Macrophages/immunology , Macrophages/drug effects , Mycobacterium tuberculosis/drug effects , Mycobacterium tuberculosis/growth & development , Tuberculosis/drug therapy , Tuberculosis/microbiology , Disease Models, Animal , Mycobacterium avium/drug effects , Lysosomes/drug effects , Lysosomes/metabolism , Lysosomes/microbiologyABSTRACT
Increasingly prevalent, nontuberculous mycobacteria (NTM) infections affect approximately 20% of people with cystic fibrosis (CF). Previous studies of CF sputum identified lower levels of the host metabolite itaconate in those infected with NTM. Itaconate can inhibit the growth of M. tuberculosis (MTB) in vitro via the inhibition of the glyoxylate cycle enzyme (ICL), but its impact on NTM is unclear. To test itaconic acid's (IA) effect on NTM growth, laboratory and CF clinical strains of Mycobacterium abscessus and Mycobacterium avium were cultured in 7H9 minimal media supplemented with 1-10 mM of IA and short-chain fatty acids (SCFA). M. avium and M. abscessus grew when supplemented with SCFAs, whereas the addition of IA (≥ 10 mM) completely inhibited NTM growth. NTM supplemented with acetate or propionate and 5 mM IA displayed slower growth than NTM cultured with SCFA and ≤ 1 mM of IA. However, IA's inhibition of NTM was pH dependent; as similar and higher quantities (100 mM) of pH adjusted IA (pH 7) did not inhibit growth in vitro, while in an acidic minimal media (pH 6.1), 1 to 5 mM of non-pH adjusted IA inhibited growth. None of the examined isolates displayed the ability to utilize IA as a carbon source, and IA added to M. abscessus isocitrate lyase (ICL) decreased enzymatic activity. Lastly, the addition of cell-permeable 4-octyl itaconate (4-OI) to THP-1 cells enhanced NTM clearance, demonstrating a potential role for IA/itaconate in host defense against NTM infections.
Subject(s)
Succinates , Succinates/pharmacology , Succinates/metabolism , Humans , Hydrogen-Ion Concentration , Nontuberculous Mycobacteria/drug effects , Nontuberculous Mycobacteria/growth & development , THP-1 Cells , Mycobacterium Infections, Nontuberculous/microbiology , Mycobacterium Infections, Nontuberculous/drug therapy , Mycobacterium avium/drug effects , Mycobacterium avium/growth & development , Mycobacterium abscessus/drug effects , Mycobacterium abscessus/growth & development , Mycobacterium abscessus/metabolismABSTRACT
BACKGROUND: Mycobacterium avium is associated with pulmonary disease in otherwise healthy adults. Several clarithromycin-refractory cases have been reported, including some cases caused by clarithromycin-susceptible strains. OBJECTIVES: To characterize the reason for the discrepancy between clinical response and antibiotic susceptibility results. METHODS: We conducted population analysis of clarithromycin-tolerant and heteroresistant subpopulations of M. avium cultured in vitro and in homogenates of infected lungs of mice. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were determined for 28 M. avium and two M. kansasii strains. Mice were intranasally infected with M. avium and treated with or without clarithromycin (100 mg/kg) thrice weekly. They were sacrificed on day 35 and the bacteria in lung homogenates were tested for clarithromycin resistance. Population analysis assays were performed based on colony growth on plates containing two-fold dilutions of clarithromycin. RESULTS: The MBC/MIC ratios were ≥8 in all 28 strains of M. avium tested. In the population analysis assay, several colonies were observed on the plates containing clarithromycin concentrations above the MIC (2-64 mg/L). No growth of M. kansasii colonies was observed on the plates containing clarithromycin concentrations ≥2 mg/L. M. avium in the homogenates of infected lungs showed clearer clarithromycin-resistant subpopulations than in vitro, regardless of clarithromycin exposure. CONCLUSION: M. avium shows intrinsic heterogeneous resistance (heteroresistance) to clarithromycin. This may explain the observed discrepancies between clarithromycin susceptibility testing results and clinical response to clarithromycin treatment. Further studies are needed to confirm a link between heteroresistance and clinical outcomes.
Subject(s)
Clarithromycin , Drug Resistance, Bacterial , Microbial Sensitivity Tests , Mycobacterium avium , Clarithromycin/pharmacology , Clarithromycin/therapeutic use , Animals , Mice , Mycobacterium avium/drug effects , Lung/microbiology , Female , Anti-Bacterial Agents/pharmacology , Anti-Bacterial Agents/therapeutic use , HumansABSTRACT
Mycobacterium avium complex pulmonary disease (MAC-PD) requires long-term treatment. We analyzed the outcomes of 992 MAC-PD patients according to disease severity and compared the outcomes of intermittent and daily therapy for mild disease. Patients were divided into groups according to severity using the body mass index, age, cavity, erythrocyte sedimentation rate, and sex (BACES) system, and culture conversion rates were evaluated. We also evaluated the effects of intermittent treatment on the culture conversion rates in mild disease group. Using the BACES, 992 patients were divided into mild (n = 331), moderate (n = 503), and severe (n = 158) disease groups, and culture conversion at the end of treatment was achieved in 85% (282/331), 80% (403/503), and 61% (97/158), respectively. Differences in culture conversion among the severity groups were significant (p < 0.001). In patients with mild disease, culture conversion rates were similar between intermittent (84%, 166/198) and daily (87%, 116/133) treatment (p = 0.396), and intermittent antibiotic therapy did not negatively impact culture conversion (adjusted hazard ratio 1.08; confidence interval 0.83-1.41; p = 0.578). MAC-PD patients with mild disease had higher culture conversion rates. Daily and intermittent therapy yielded similar culture conversion rates for mild disease. Treatment strategies with lower pill burden may be applicable in mild MAC-PD.
Subject(s)
Lung Diseases/drug therapy , Lung/drug effects , Mycobacterium avium/drug effects , Tuberculosis, Avian/drug therapy , Aged , Animals , Antitubercular Agents/administration & dosage , Body Mass Index , Ethambutol/administration & dosage , Female , Humans , Lung/microbiology , Lung/pathology , Lung Diseases/microbiology , Lung Diseases/pathology , Male , Mycobacterium avium/pathogenicity , Severity of Illness Index , Sputum/drug effects , Sputum/microbiology , Treatment Outcome , Tuberculosis, Avian/microbiology , Tuberculosis, Avian/pathologyABSTRACT
The aminobenzimidazole SPR719 targets DNA gyrase in Mycobacterium tuberculosis. The molecule acts as inhibitor of the enzyme's ATPase located on the Gyrase B subunit of the tetrameric Gyrase A2B2 protein. SPR719 is also active against non-tuberculous mycobacteria (NTM) and recently entered clinical development for lung disease caused by these bacteria. Resistance against SPR719 in NTM has not been characterized. Here, we determined spontaneous in vitro resistance frequencies in single step resistance development studies, MICs of resistant strains, and resistance associated DNA sequence polymorphisms in two major NTM pathogens Mycobacterium avium and Mycobacterium abscessus. A low-frequency resistance (10-8/CFU) was associated with missense mutations in the ATPase domain of the Gyrase B subunit in both bacteria, consistent with inhibition of DNA gyrase as the mechanism of action of SPR719 against NTM. For M. abscessus, but not for M. avium, a second, high-frequency (10-6/CFU) resistance mechanism was observed. High-frequency SPR719 resistance was associated with frameshift mutations in the transcriptional repressor MAB_4384 previously shown to regulate expression of the drug efflux pump system MmpS5/MmpL5. Our results confirm DNA gyrase as target of SPR719 in NTM and reveal differential resistance development in the two NTM species, with M. abscessus displaying high-frequency indirect resistance possibly involving drug efflux. IMPORTANCE Clinical emergence of resistance to new antibiotics affects their utility. Characterization of in vitro resistance is a first step in the profiling of resistance properties of novel drug candidates. Here, we characterized in vitro resistance against SPR719, a drug candidate for the treatment of lung disease caused by non-tuberculous mycobacteria (NTM). The identified resistance associated mutations and the observed differential resistance behavior of the two characterized NTM species provide a basis for follow-up studies of resistance in vivo to further inform clinical development of SPR719.
Subject(s)
Anti-Bacterial Agents/pharmacology , Mycobacterium Infections, Nontuberculous/microbiology , Mycobacterium abscessus/drug effects , Mycobacterium avium/drug effects , Topoisomerase II Inhibitors/pharmacology , Bacterial Proteins/genetics , Bacterial Proteins/metabolism , Benzimidazoles/pharmacology , DNA Gyrase/genetics , DNA Gyrase/metabolism , Drug Resistance, Bacterial , Humans , Microbial Sensitivity Tests , Mutation , Mycobacterium abscessus/enzymology , Mycobacterium abscessus/genetics , Mycobacterium abscessus/growth & development , Mycobacterium avium/enzymology , Mycobacterium avium/genetics , Mycobacterium avium/growth & developmentABSTRACT
Mycobacterium avium is an emerging opportunistic pathogen, globally. Infections caused by M. avium are laborious to treat and could result in drug resistance. This review discusses the importance of many factors including the cell wall in M. avium pathogenesis, since this unique structure modulates the pathogen's ability to thrive in various hosts and environmental niches including conferring resistance to killing by antimicrobials. More research efforts in future are solicited to develop novel therapeutics targeting M. avium. The complete eradication of M. avium infection in immunocompromised individuals would need a deeper understanding of the source of infection, unique underlying mechanisms and its uncharacterized pathways. This could, perhaps in future, hold the key to target and treat M. avium more effectively.
Subject(s)
Anti-Infective Agents , Mycobacterium avium-intracellulare Infection , Anti-Infective Agents/pharmacology , Cell Wall , Humans , Mycobacterium avium/drug effects , Mycobacterium avium-intracellulare Infection/drug therapyABSTRACT
Considering the promising previous results on the remarkable activity exhibited by cobalt(III) and manganese(II) thiosemicarbazone compounds as antibacterial agents, the present study aimed to prepare and then evaluate the antibacterial activity of two different types of Cu(II) complexes based on a 2-acetylpyridine-N(4)-methyl-thiosemicarbazone ligand (Hatc-Me), a monomer complex [CuCl(atc-Me)] and a novel dinuclear complex [{Cu(µ-atc-Me)}2µ-SO4]. The compounds were characterized by infrared spectra, ultraviolet visible and CHN elemental analysis. In addition, the crystalline structures of the complexes were determined by single-crystal X-ray diffraction. In both cases, the Schiff base ligand coordinated in a tridentate mode via the pyridine nitrogen, imine nitrogen and sulfur atoms. The two Cu(II) atoms in the dimer are five coordinate, consisting of three NNS-donor atoms from the thiosemicarbazone ligand connected by a sulfate bridge. The Hirshfeld surface and energy framework of the complexes were additionally analyzed to verify the intermolecular interactions. The biological activity of the Cu(II) salts, the free ligand and its Cu(II) complexes was evaluated against six strains of mycobacteria including Mycobacterium tuberculosis. The complexes showed promising results as antibacterial agents for M. avium and M. tuberculosis, which ranged from 6.12 to 12.73 µM. Furthermore, molecular docking analysis was performed and the binding energy of the docked compound [{Cu(µ-atc-Me)}2µ-SO4] with M. tuberculosis and M. avium strains were extremely favorable (-11.11 and - 14.03 kcal/mol, respectively). The in silico results show that the complexes are potential candidates for the development of new antimycobacterial drugs.
Subject(s)
Antitubercular Agents/pharmacology , Coordination Complexes/pharmacology , Thiosemicarbazones/pharmacology , Antitubercular Agents/chemical synthesis , Antitubercular Agents/metabolism , Antitubercular Agents/pharmacokinetics , Bacterial Proteins/metabolism , Coordination Complexes/chemical synthesis , Coordination Complexes/metabolism , Coordination Complexes/pharmacokinetics , Copper/chemistry , Ligands , Microbial Sensitivity Tests , Molecular Docking Simulation , Molecular Structure , Mycobacterium avium/drug effects , Mycobacterium kansasii/drug effects , Mycobacterium tuberculosis/drug effects , Protein Binding , Structure-Activity Relationship , Thermodynamics , Thiosemicarbazones/chemical synthesis , Thiosemicarbazones/metabolism , Thiosemicarbazones/pharmacokineticsABSTRACT
Introduction. Mycobacterium avium complex (MAC) has been reported as the most common aetiology of lung disease involving nontuberculous mycobacteria.Hypothesis. Antimicrobial susceptibility and clinical characteristics may differ between Mycobacterium avium and Mycobacterium intracellulare.Aim. We aimed to evaluate the differences in antimicrobial susceptibility profiles between two major MAC species (Mycobacterium avium and Mycobacterium intracellulare) from patients with pulmonary infections and to provide epidemiologic data with minimum inhibitory concentration (MIC) distributions.Methodology. Between January 2019 and May 2020, 45 M. avium and 242 M. intracellulare isolates were obtained from Shanghai Pulmonary Hospital. The demographic and clinical characteristics of patients were obtained from their medical records. The MICs of 13 antimicrobials were determined for the MAC isolates using commercial Sensititre SLOWMYCO MIC plates and the broth microdilution method, as recommended by the Clinical and Laboratory Standards Institute (CLSI; Standards M24-A2). MIC50 and MIC90 values were derived from the MIC distributions.Results. M. intracellulare had higher resistance rates than M. avium for most tested antimicrobials except clarithromycin, ethambutol, and ciprofloxacin. Clarithromycin was the most effective antimicrobial against both the M. avium (88.89â%) and M. intracellulare (91.32â%) isolates, with no significant difference between the species (P=0.601). The MIC90 of clarithromycin was higher for M. avium (32 µg ml-1) than M. intracellulare (8 µg ml-1). The MIC50 of rifabutin was more than four times higher for M. intracellulare (1 µg ml-1) than M. avium (≤0.25 µg ml-1). The percentages of patients aged >60 years and patients with sputum, cough, and cavitary lesions were significantly higher than among patients with M. intracellulare infection than M. avium infections.Conclusions. The pulmonary disease caused by distinct MAC species had different antimicrobial susceptibility, symptoms, and radiographic findings.
Subject(s)
Anti-Bacterial Agents/pharmacology , Lung Diseases/microbiology , Mycobacterium avium Complex/drug effects , Mycobacterium avium-intracellulare Infection/microbiology , Mycobacterium avium/drug effects , Adult , Aged , China , Ciprofloxacin/pharmacology , Clarithromycin/pharmacology , Cough , Doxycycline/pharmacology , Drug Resistance, Bacterial , Female , Humans , Lung/diagnostic imaging , Lung Diseases/physiopathology , Male , Microbial Sensitivity Tests , Middle Aged , Mycobacterium avium/isolation & purification , Mycobacterium avium Complex/isolation & purification , Mycobacterium avium-intracellulare Infection/diagnosis , Mycobacterium avium-intracellulare Infection/physiopathology , Radiography , SputumSubject(s)
Infliximab/adverse effects , Mycobacterium avium/pathogenicity , Tuberculosis/etiology , Crohn Disease/drug therapy , Gastrointestinal Agents/adverse effects , Gastrointestinal Agents/pharmacology , Gastrointestinal Agents/therapeutic use , Humans , Infliximab/pharmacology , Infliximab/therapeutic use , Male , Middle Aged , Mycobacterium avium/drug effects , Pleural Effusion/diagnostic imaging , Pleural Effusion/etiology , Tomography, X-Ray Computed/methods , Tuberculosis/microbiologyABSTRACT
Mycobacterium avium complex is a causative organism for refractory diseases. In this study, we examined the effects of N-acetyl-cysteine on M. avium infection in vitro and in vivo. N-acetyl-cysteine treatment suppressed the growth of M. avium in A549 cells in a concentration-dependent manner. This effect was related to the induction of the antibacterial peptide human ß-defensin-2. In a mouse model, N-acetyl-cysteine treatment significantly reduced the number of bacteria in the lungs and induced murine ß-defensin-3. In interleukin-17-deficient mice, the effects of N-acetyl-cysteine disappeared, indicating that these mechanisms may be mediated by interleukin-17. Moreover, an additional reduction in bacterial load was observed in mice administered N-acetyl-cysteine in combination with clarithromycin. Our findings demonstrate the potent antimycobacterial effects of N-acetyl-cysteine against M. avium by inducing antimicrobial peptide, suggesting that N-acetyl-cysteine may have applications as an alternative to classical treatment regimens.
Subject(s)
Acetylcysteine/pharmacology , Antitubercular Agents/pharmacology , Mycobacterium avium-intracellulare Infection/drug therapy , Mycobacterium avium/drug effects , beta-Defensins/metabolism , A549 Cells , Acetylcysteine/therapeutic use , Animals , Antitubercular Agents/therapeutic use , Bacterial Load/drug effects , Disease Models, Animal , Humans , Interleukin-17/metabolism , Lung/drug effects , Lung/microbiology , Mice , Mycobacterium avium/growth & development , Mycobacterium avium-intracellulare Infection/metabolism , Mycobacterium avium-intracellulare Infection/microbiology , RAW 264.7 Cells , Signal TransductionABSTRACT
Despite early treatment with antimycobacterial combination therapy, drug resistance continues to emerge. Maintenance of redox homeostasis is essential for Mycobacterium avium (M. avium) survival and growth. The aim of the present study was to investigate the antimycobacterial activity of two pro-glutathione (pro-GSH) drugs that are able to induce redox stress in M. avium and to modulate cytokine production by macrophages. Hence, we investigated two molecules shown to possess antiviral and immunomodulatory properties: C4-GSH, an N-butanoyl GSH derivative; and I-152, a prodrug of N-acetyl-cysteine (NAC) and ß-mercaptoethylamine (MEA). Both molecules showed activity against replicating M. avium, both in the cell-free model and inside macrophages. Moreover, they were even more effective in reducing the viability of bacteria that had been kept in water for 7 days, proving to be active both against replicating and non-replicating bacteria. By regulating the macrophage redox state, I-152 modulated cytokine production. In particular, higher levels of interferon-gamma (IFN-γ), interleukin 1 beta (IL-1ß), IL-18 and IL-12, which are known to be crucial for the control of intracellular pathogens, were found after I-152 treatment. Our results show that C4-GSH and I-152, by inducing perturbation of redox equilibrium, exert bacteriostatic and bactericidal activity against M. avium. Moreover, I-152 can boost the host response by inducing the production of cytokines that serve as key regulators of the Th1 response.
Subject(s)
Acetylcysteine/analogs & derivatives , Anti-Bacterial Agents/pharmacology , Cysteamine/analogs & derivatives , Glutathione/pharmacology , Mycobacterium avium/drug effects , Oxidation-Reduction/drug effects , Acetylcysteine/pharmacology , Cysteamine/pharmacology , Cytokines/metabolism , Glutathione/analogs & derivatives , Humans , Macrophages/metabolism , Microbial Sensitivity Tests , Oxidative Stress/drug effectsABSTRACT
OBJECTIVES: Characteristics of the Mycobacterium avium-intracellulare complex pulmonary disease (MAC-PD) caused by distinct subspecies remain uncertain. METHODS: This study was conducted from 2013-2015 in three hospitals in Taiwan. RESULTS: Among the 144 patients with MAC-PD, 57 (39.6%), 37 (25.7%), 37 (25.7%), and 13 (9.0%) were infected with Mycobacterium intracellulare subspecies intracellulare (MIsI), Mycobacterium avium subspecies hominissuis (MAsH), Mycobacterium intracellulare subspecies chimaera (MIsC), and others, respectively. Patients with MAsH-PD were younger (p = 0.010) with higher human immunodeficiency virus infection rates (27.0%, 0.0%, 0.0%, and 7.7% for MAsH-PD, MIsC-PD, MIsI-PD, and others, respectively; p < 0.001). Twenty-two (15.3%) patients reported spontaneous culture-negative conversion, but 15 (10.4%) and 33 (22.9%) patients developed radiographic progression and unfavorable outcomes, especially MAsH-PD. The susceptibility rates to clarithromycin and inhaled amikacin were both 98.6%. MAsH demonstrated the lowest rate of resistance to moxifloxacin (66.7%, 97.3%, 89.1%, and 92.3% for MAsH-PD, MIsC-PD, MIsI-PD, and others, respectively; p = 0.001) and MIsI isolates had the highest rate of resistance to intravenous amikacin (25%, 13.5%, 38.2%, and 15.4% for MAsH-PD, MIsC-PD, MIsI-PD, and others, respectively; p = 0.024). CONCLUSIONS: Pulmonary disease caused by distinct MAC subspecies had different outcomes and drug susceptibility. The local prevalence of species needs to be monitored.
Subject(s)
Anti-Bacterial Agents/pharmacology , Lung Diseases/microbiology , Mycobacterium avium-intracellulare Infection/microbiology , Mycobacterium avium/drug effects , Adult , Aged , Aged, 80 and over , Amikacin/pharmacology , Clarithromycin/pharmacology , Drug Resistance, Bacterial , Female , Humans , Male , Microbial Sensitivity Tests , Middle Aged , Moxifloxacin/pharmacology , Mycobacterium avium/genetics , Mycobacterium avium/isolation & purification , Mycobacterium avium-intracellulare Infection/immunology , Taiwan , Young AdultABSTRACT
The marine actinomycete strain OPMA02852, identified as the genus Streptomyces, was found to produce anti-mycobacterial compounds against Mycobacterium avium complex (MAC). One new compound, designated as steffimycin E (1), was isolated together with three known steffimycins (steffimycin (2), 10-dihydrosteffimycin (3), and 8-demethoxysteffimycin (4)) from the culture broth of this producing microorganism by solvent extraction, ODS column chromatography, and preparative HPLC. Compound 1 has a tetracyclic quinone structure with a sugar moiety. Compound 1 exhibited anti-mycobacterial activity against M. intracellulare, M. bovis BCG, and M. smegmatis.
Subject(s)
Anthracyclines/pharmacology , Antitubercular Agents/pharmacology , Mycobacterium avium Complex/drug effects , Mycobacterium avium/drug effects , Streptomyces/chemistry , Anthracyclines/chemistry , Antitubercular Agents/chemistry , Cell Line, Tumor , HeLa Cells , Humans , Mycobacterium avium-intracellulare Infection/drug therapyABSTRACT
Infections with nontuberculous mycobacteria (NTM) have a poor prognosis in patients with underlying respiratory diseases. Clofazimine (CFZ) showed both experimental and clinical promising results against clinically relevant NTM. However, there are no data on CFZ in combination with the current recommended treatment; therefore, we aimed to study its in vivo activity in an aerosol mouse model of Mycobacterium avium In an aerosol infection BALB/c mouse model using M. avium strain Chester, we treated 58 mice with four combinations of rifampin (RIF) at 10 mg/kg, CFZ at 25 mg/kg, and clarithromycin (CLR) and ethambutol (EMB) at 100 mg/kg. Treatment efficacy was assessed on the basis of lung CFU counts after 2 (M2) and 4 (M4) months of treatment. At M2, CLR-RIF-EMB was slightly but significantly more efficient than CFZ-RIF-EMB (3.02 ± 0.12 versus 3.55 ± 0.28, respectively, P < 0.01), whereas CLR-CFZ-EMB and CLR-CFZ-RIF-EMB dramatically decreased lung CFU counts by 4.32 and 4.47 log10, respectively, compared to untreated group. At M4, CLR-RIF-EMB was significantly more efficient than CFZ-RIF-EMB (2 ± 0.53 versus 2.66 ± 0.22, respectively, P = 0.01). The addition of CLZ to CLR dramatically decreased the lung CFU count, with CFU counts 5.41 and 5.79 log10 lower in the CLR-CFZ-EMB and CLR-CFZ-RIF-EMB groups, respectively, than in the untreated group. The addition of CFZ to CLR seems to improve the efficacy of CLR as early as M2 and was confirmed at M4. CFZ, in addition to RIF and EMB, on the other hand, is less effective than CLR-RIF-EMB. These results need to be confirmed by similar studies along with CFZ potential for shortening treatment.
Subject(s)
Antitubercular Agents/therapeutic use , Clarithromycin/therapeutic use , Clofazimine/therapeutic use , Mycobacterium avium-intracellulare Infection/drug therapy , Mycobacterium avium/drug effects , Aerosols , Animals , Antitubercular Agents/administration & dosage , Clarithromycin/administration & dosage , Clofazimine/pharmacology , Colony Count, Microbial , Drug Synergism , Ethambutol/therapeutic use , Female , Lung/microbiology , Mice , Mice, Inbred BALB C , Microbial Sensitivity Tests , Mycobacterium avium-intracellulare Infection/microbiology , Rifampin/therapeutic use , Treatment OutcomeABSTRACT
Abstract Propolis is a resinous substance collected and processed by Apis mellifera from parts of plants, buds and exudates. In Minas Gerais (MG) state, Brazil, green propolis is produced from the collection of resinous substance found in shoot apices of Baccharis dracunculifolia. This paper aims to investigate the chemical composition and in vitro antioxidant, anti-Helicobacter pylori, antimycobacterial and antiproliferative activities of essential oil (EO) from Brazilian green propolis (BGP-EO). The oil showed high antibacterial activity against H. pylori (MIC = 6.25 µg/mL), Mycobacterium avium (MIC = 62.5 µg/mL) and M. tuberculosis (MIC = 64 µg/mL). Its antioxidant activity was evaluated in vitro by both DPPH (IC50 = 23.48 µg/mL) and ABTS (IC50 = 32.18 µg/mL) methods. The antiproliferative activity in normal (GM07492A, lung fibroblasts) and tumor cell lines (MCF-7, HeLa and M059J) was analyzed by the XTT assay. BGP-EO showed inhibition of normal cell growth at 68.93 ± 2.56 µg/mL. Antiproliferative activity was observed against human tumor cell lines, whose IC50 values were 56.17, 66.43 and -65.83 µg/mL for MCF-7, HeLa and M059J cells, respectively. Its major constituents, which were determined by GC-FID and GC-MS, were carvacrol (20.7 %), acetophenone (13.5 %), spathulenol (11.0 %), (E)-nerolidol (9.7 %) and β-caryophyllene (6.2 %). These results showed the effectiveness of BGP-EO as a natural product which has promising biological activities.
Subject(s)
Propolis/chemistry , Anti-Infective Agents/pharmacology , Antioxidants/pharmacology , Brazil , Oils, Volatile/therapeutic use , Helicobacter pylori/drug effects , Mycobacterium avium/drug effects , Mycobacterium tuberculosis/drug effectsABSTRACT
Polycations, mimicking activity of antibacterial peptides, belong to an important class of molecules investigated as a support or as an alternative to antibiotics. In this work, studies of modified linear amphiphilic statistical polymethyloxazoline (PMOX) and polyethyleneimine copolymers (PMOX_PEI) series are presented. Variation of PEI content in the structure results in controllable changes of polymeric aggregates zeta potential. The structure with the highest positive charge shows the best antimicrobial activity, well visible in tests against model Gram-positive and Gram-negative bacteria, fungi, and mycobacterium strains. The polymer toxicity is evaluated with MTT and hemolysis assay as a reference. Quartz crystal microbalance (QCM-D) is used to investigate interaction between polycations and a model lipid membrane. Polymer activity correlates well with molecular structure, showing that amphiphilic component is altering polymer behavior in contact with the lipid bilayer.
Subject(s)
Anti-Infective Agents/pharmacology , Lipid Bilayers/chemistry , Polyamines/pharmacology , Polyethyleneimine/pharmacology , Anti-Infective Agents/chemical synthesis , Antimicrobial Cationic Peptides/chemistry , Candida albicans/drug effects , Candida albicans/growth & development , Erythrocytes/drug effects , Escherichia coli/drug effects , Escherichia coli/growth & development , Hemolysis/drug effects , Humans , Microbial Sensitivity Tests , Molecular Mimicry , Molecular Structure , Mycobacterium avium/drug effects , Mycobacterium avium/growth & development , Mycobacterium bovis/drug effects , Mycobacterium bovis/growth & development , Mycobacterium tuberculosis/drug effects , Mycobacterium tuberculosis/growth & development , Nontuberculous Mycobacteria/drug effects , Nontuberculous Mycobacteria/growth & development , Polyamines/chemical synthesis , Polyelectrolytes/chemistry , Polyethyleneimine/chemical synthesis , Staphylococcus aureus/drug effects , Staphylococcus aureus/growth & development , Static Electricity , Structure-Activity RelationshipABSTRACT
BACKGROUND: Although fluoroquinolones are considered as alternative therapies of pulmonary Mycobacterium avium complex (MAC) disease, the association between fluoroquinolone resistance and MAC genotypes in clinical isolates from individuals not previously treated for MAC infection is not fully clear. METHODS: Totals of 154 M. avium isolates and 35 Mycobacterium intracellulare isolates were obtained from treatment-naïve patients with pulmonary MAC disease at the diagnosis of MAC infection at 8 hospitals in Japan. Their susceptibilities of moxifloxacin were determined by broth microdilution methods. Moxifloxacin-resistant isolates were examined for mutations of gyrA and gyrB. Variable numbers of tandem repeats (VNTR) assay was performed using 15 M. avium VNTR loci and 16 M. intracellulare VNTR loci. RESULTS: Moxifloxacin susceptibility was categorized as resistant and intermediate for 6.5% and 16.9%, respectively, of M. avium isolates and 8.6% and 17.1% of M. intracellulare isolates. Although the isolates of both species had amino acid substitutions of Thr 96 and Thr 522 at the sites corresponding to Ser 95 in the M. tuberculosis GyrA and Gly 520 in the M. tuberculosis GyrB, respectively, these substitutions were observed irrespective of susceptibility and did not confer resistance. The VNTR assays showed revealed three clusters among M. avium isolates and two clusters among M. intracellulare isolates. No significant differences in moxifloxacin resistance were observed among these clusters. CONCLUSIONS: Although resistance or intermediate resistance to moxifloxacin was observed in approximately one-fourth of M. avium and M. intracellulare isolates, this resistance was not associated with mutations in gyrA and gyrB or with VNTR genotypes.
Subject(s)
Anti-Bacterial Agents/pharmacology , Moxifloxacin/pharmacology , Mycobacterium avium Complex/drug effects , Mycobacterium avium-intracellulare Infection/drug therapy , Mycobacterium avium/drug effects , Anti-Bacterial Agents/therapeutic use , DNA Gyrase/genetics , Drug Resistance, Bacterial/genetics , Genotype , Humans , Japan , Microbial Sensitivity Tests , Minisatellite Repeats/genetics , Moxifloxacin/therapeutic use , Mutation , Mycobacterium avium/genetics , Mycobacterium avium/isolation & purification , Mycobacterium avium Complex/genetics , Mycobacterium avium Complex/isolation & purification , Mycobacterium avium-intracellulare Infection/microbiologyABSTRACT
Nontuberculous mycobacteria (NTM) are ubiquitous microbes belonging to the Mycobacterium genus. Among all NTM pathogens, M. avium is one of the most frequent agents causing pulmonary disease, especially in immunocompromised individuals and cystic fibrosis patients. Recently, we reported the first ad hoc designed M. avium efflux pump inhibitor (EPI; 1b) able to strongly boost clarithromycin (CLA) MIC against different M. avium strains. Since the 3-phenylquinolone derivative 1b suffered from toxicity issues toward human macrophages, herein we report a two-pronged medicinal chemistry workflow for identifying new potent and safe NTM EPIs. Initially, we followed a computational approach exploiting our pharmacophore models to screen FDA approved drugs and in-house compounds to identify "ready-to-use" NTM EPIs and/or new scaffolds to be optimized in terms of EPI activity. Although nicardipine 2 was identified as a new NTM EPI, all identified molecules still suffered from toxicity issues. Therefore, based on the promising NTM EPI activity of 1b, we undertook the design, synthesis, and biological evaluation of new 3-phenylquinolones differently functionalized at the C6/C7 as well as N1 positions. Among the 27 synthesized 3-phenylquinolone analogues, compounds 11b, 12b, and 16a exerted excellent NTM EPI activity at concentrations below their CC50 on human cells, with derivative 16a being the most promising compound. Interestingly, 16a also showed good activity in M. avium-infected macrophages both alone as well as in combination with CLA. The antimycobacterial activity observed for 16a only when tested in the ex vivo model suggests a high therapeutic potential of EPIs against M. avium, which seems to need functional efflux pumps to establish intracellular infections.
Subject(s)
Adjuvants, Immunologic/therapeutic use , Anti-Bacterial Agents/pharmacology , Benzoquinones/chemistry , Membrane Transport Modulators/pharmacology , Membrane Transport Proteins/metabolism , Mycobacterium/drug effects , Computer Simulation , Drug Synergism , Humans , Macrophages/drug effects , Macrophages/microbiology , Mycobacterium avium/drug effectsABSTRACT
BACKGROUND: Nontuberculous mycobacterial (NTM) disease is commonly an opportunistic infection frequently found in immunocompromised individuals, but sometimes can also be found in the immunocompetent hosts, especially in East Asians. The NTM separation rate in China is increasing, which reminds us to focus on NTM infections in immunocompromised populations. CASE PRESENTATION: A 43-year-old woman with a recurrent fever for more than 8-month and a right forehead surgical wounds unhealed for more than 6-month was admitted to our hospital on February 22, 2018. On arrival, several elliptic ulcers were obvious on the right forehead with pus and fibrin exudation, and the skin around the lesions was tender, reddish, no sense of fluctuation. The result of HIV serology test was negative. CD4+ T cell count was normal and tuberculosis antibody was negative. CT of the chest and head showed bone destruction. Skin biopsy on the right forehead was performed on March 13, 2018, and pathological examination of the excisional biopsy specimen found inflammatory granuloma and suppurative inflammatory changes. Broad-spectrum antibiotics were treated but the effect seemed discontent. Then debridement and skin grafting were performed on the right frontal ulcer under general anesthesia on April 3, 2018. The skin tissue culture that resected on March 13, 2018 found Nontuberculous mycobacteria grown after 78 days, so clarithromycin, ethambutol, protionamide, and amoxicillin clavulanate potassium were prescribed for anti-nontuberculous mycobacteria treatment beginning on May 31, 2018. In reviewing the case, Mycobacterium avium (M. avium) was identified in the skin tissue resected on April 3, 2018 by polymerase chain reaction (PCR) and the serum test of anti-interferon-γ autoantibodies was positive. CONCLUSIONS: This is a case report of "Mycobacterium avium SSTI (skin and soft tissue infection) and OM (osteomyelitis) with possible secondary immunodeficiency syndrome induced by anti-interferon-γ autoantibody".
Subject(s)
Interferon-gamma/immunology , Mycobacterium Infections, Nontuberculous/drug therapy , Mycobacterium avium/pathogenicity , Osteomyelitis/etiology , Soft Tissue Infections/drug therapy , Adult , Amoxicillin-Potassium Clavulanate Combination/therapeutic use , Anti-Bacterial Agents/therapeutic use , Autoantibodies , Clarithromycin/therapeutic use , Ethambutol/therapeutic use , Female , Granuloma/microbiology , Granuloma/surgery , Humans , Microbial Sensitivity Tests , Mycobacterium Infections, Nontuberculous/microbiology , Mycobacterium avium/drug effects , Mycobacterium avium/genetics , Osteomyelitis/immunology , Osteomyelitis/therapy , Scalp/pathology , Soft Tissue Infections/microbiologyABSTRACT
Ruxolitinib is a JAK-1/JAK-2 inhibitor indicated for the treatment of polycythemia vera and primary or secondary myelofibrosis. Only one patient (0.2%) was diagnosed with tuberculosis among the 485 patients receiving ruxolitinib in the four pivotal trials. Fourteen cases of tuberculosis have since been reported. We observed two (3%) mycobacterial infections (one due to Mycobacterium tuberculosis and one due to Mycobacterium avium complex) in our cohort of 65 patients receiving ruxolitinib. This observation suggests that the rate of mycobacterial infection might be higher than that observed in the pivotal trials and that atypical mycobacterial infections can also occur.